Flat Roof Rafter Vs Joists

The rafters in a flat roof serve as ceiling joists for the space below.

Flat roof rafter vs joists.

Ceiling joists can be on both low sloped roofs and high sloped roofs and help to prevent racking and spreading of your rafters or walls which could lead to sagging. In traditional timber they are nominally 2 inches thick and typically 8 to 10 inches wide. They are nailed securely to exterior wall plates and to each other. Rafters are the building components that run diagonally from the wall plate to the apex of a roof structure.

Rafters form the foundation for attachment of the roof boards onto which the final roof covering is fixed. The size of rafters for a flat roof depends on the horizontal span of the building the type and grade of timber used and the load on the roof. A ceiling joist is simply a horizontal framing member that runs between walls or rafters to support a ceiling say editors while a rafter tie is a horizontal framing member that runs between rafters to resist the outward thrust of the rafters. As mentioned above a 2 4 spf shed roof rafter can span 11.

Conventional framing the first thing to understand is how a roof framed with wood i joists differs structurally from a traditional stick framed roof. Both of these are for light roof loads. An syp rafter can span 11. In a typical roof framed with dimension lumber the rafters rest on the exterior wall top plate at the lower end and bear against a ridge board at the top.

Trusses and rafters have many common parts including the sloping rafter boards and a bottom joists that form the ceiling of the space below. Corbett grace their parents and even their kids are learning a lot about the many ways a few right many wrong to build a high performance home. The main difference between joist and rafter is that the joist is a horizontal structural element transferring load from flooring to beams typically running perpendicular to beams and rafter is a structural members in architecture. They are important load bearing structural elements.